"Blue Ice 5500K• Stronger blue component for maximum vegetative growth Developed by distinguished physicists and leading agricultural researchers, the SUNMASTER line has been built on the marvelous versatility and flexibility of metal halide technology. By blending specific halides in the arc tubes, they have created lamps which offer significantly more usable light energy for hydroponics and horticultural gardening. Moreover, each SUNMASTER lamp has been customized to meet the diverse nutrition requirements of plants at various stages of their growth cycles. So, while the sun may come and go, SUNMASTER lamps are sure to consistently provide new levels of quality and productivity. If not the sun... SUNMASTER All Sunmaster® lamps are enhanced for superior operation on high frequency digital ballasts. Each electrode in the lamp uses a special blend of Nickel (Ni 65%) and Copper (Cu 30%). With Sunmaster's spectral families, each lamp is tailored to promote optimum development at each plant growth stage. Conversion bulb converts 600W HPS ballast to MH LAMP DESCRIPTION: LM.600W.U25.5.5K SUNMASTER CODE: 61492-NA"